immune system

Question 1

What is a monoclonal antibody

Answer 1

an antibody produced by a single clone of cells

Question 2

outline the process of phagocytosis

Answer 2

pathogen engulfed and put into phagosome
lysosomes fuse with phagosome
lysosomes release lysozymes that hydrolyse pathogen
products absorbed by phagocyte

Question 3

what is an antigen

Answer 3

a molecule that triggers an immune response

by lymphocytes

Question 4

where in the body do B-lympocytes mature

Answer 4

In the bone marrow

Question 5

Describe how B-lymphocytes respond when they are stimulated by antigens.

Answer 5

they divide by mitosis and produce plasma cells which make antibodies and memory cells

Question 6

what is vaccination

Answer 6

the injection of dead or attenuated pathogens or antigen preperation that stimulate the formation of memory cells

Question 7

what do helper t cells do

Answer 7

release cytokines that activate and stimulate phagocytes cytotoxic t cells and B-cells

Question 8

what are B lymphoyctes

Answer 8

they are a type of white blood cell that produce antibodies

Question 9

outline the process of clonal selection

Answer 9

when the antibody on a B-cell surface meets a complementary shaped antigen it binds to it.
this along with the substances from the helper t cell

Question 10

what does clonal selection cause B cells to undergo

Answer 10

divide by mitsosis to form plasma cells

Question 11

what are plasma cells

Answer 11

cells that are identical to B cells
they secrete loads of antibodies specific to the antigen
they bind to the antigens on the surface of the pathogen
form lots antigen-antibody complexes

Question 12

why does an antibody have two binding sites

Answer 12

so it can bind to two pathogens at once
this means pathogens are clumped together
this is called agglutination

Question 13

what do phagocytes to do pathogens with antibodies binded to them

Answer 13

they carry out phagocytosis on them and destroy them

Question 14

what are the two types of immune response

Answer 14

cellular and humoral response

Question 15

what is the role of cytotoxic t cells

Answer 15

they kill foreign cells and abnormal body cells

Question 16

what is the cellular response

Answer 16

The T cells and other immune cells that they interact with. form the cellular response

Question 17

what is the humoral response

Answer 17

B cells,clonal selection and the production of monoclonal antibodies form the humoral response

Question 18

name two ways pathogens cause disesase

Answer 18

releasing toxins

damaging cells/tissues

Question 19

how can monoclonal antibodies be used with anti-cancer drugs

Answer 19

cancer cells have antigens called tumour markers
monoclonal antibodies made specific to tumour markers
drugs only accumulate in bodies with cancer cells
antibody binds to markers with cancer drug attached

Question 20

how can monoclonal antibodies be used in pregnancy tests

Answer 20

application area antibodies complimentary to hgc protein.
urine applied hgc will bind to antibody on beads
urine moves up stick to test strip where hgc antibodies are
if hgc present it will go blue if it is not the beads pass through

Question 21

outline the direct elisa test

Answer 21

antigens from sample bound to well plate
detection antibody with enzyme complimentary to antigen added
if antigen is present it will be immobilised
well is washed to remove unbound antibody
substrate solution added if antibody present colour change occurs as enzyme reacts with substrate

Question 22

outline indirect elisa test(HIV test)

Answer 22

antigen bound to bottom of well plate
sample of blood is added if specific antibody present will bind to antigen
well washed out to remove unbound antibody
secondary antibody with enzyme added which can bind to antibodies well washed out again
solution added is antibody is present colour change will occur

Question 23

outline the t-lymphocyte response

Answer 23

antigen presenting cell
receptors on specific helper t cells complimentary to antigens on antigen presenting cell
attachment activates t cell to divide rapidly by mitosis and form a clone of genetically identical cells
cloned t cells either
develop into memory cells
or
stimulate the other cells into immune response and active killer t cells

Question 24

What is active immunity

Answer 24

Immunity that requires memory cells to be made
Can be obtained by vaccines, suffering disease once
It is long lasting

Question 25

What is passive immunity

Answer 25

Immunity that is obtained by an injection/giving of antibodies.

Question 26

What is natural passive immunity

Answer 26

Through the placenta or breast milk

Question 27

What is artificial passive immunity

Answer 27

Via injection

Question 28

Why may vaccination not eliminate disease

Answer 28

It fails to induce immunity in certain people
People develop disease immediately after vaccination
Pathogen may mutate frequently so antigens change frequently

Question 29

What is herd immunity?

Answer 29

Where unvaccinated people are protected because of the occurrence of the disease is reduced by the number of people who are vaccinated

Question 30

what does HIV do in the body

Answer 30

It infects and kill helper t cells
Without enough helper t cells immine system unable to mount an effective response
Immune cells don’t behave how they should